Some argue the Mexican peso has been tracking Trump's fortunes, as the Republican candidate has made Mexico a strong focus of his campaign. He has promised to build a wall along its border with the United States, and referred to Mexican migrants as "rapists."

The peso's value has been steadily climbing since late September, when it hit a low against the U.S. dollar. Since then, the peso has jumped 6.7 per cent against the American currency.

The trend comes as Trump has started dropping in the opinion polls, and it reflects the reduced optimism that Americans will put the Republican candidate in the Oval Office come next month, Shaun Osborne, chief FX strategist at Scotiabank, told The Huffington Post Canada.

The trend of the Mexican peso against the American dollar since late September. (Photo: XE.com)

"It's not a bet against a Trump presidency, just a reduced probability of a Trump win," he said.

FiveThirtyEight.com currently pegs Trump as having a 12.3 per cent chance of winning the presidency.

But Osborne urged caution, noting that polls suggested the Brexit campaign would fail. It ended up winning with 52 per cent of the vote.

"I think it's a once-bitten, twice shy issue for the markets at this point," he said.

Currency markets aren't the only indication that Trump is less likely to be president now than he was before.

Ireland-based sports bettor Paddy Power, one of Europe's biggest betting companies, said it's a "done deal" that Hillary Clinton will be America's next president.

Trump's odds of winning are now 9/2, reflecting an 18.2 per cent chance at the Oval Office.

"[Trump's] chances now look as patchy as his tan."

"Trump gave it a hell of a shot going from a rank outsider to the Republican candidate but the recent flood of revelations have halted his momentum and his chances now look as patchy as his tan," a Paddy Power spokesperson said.

The bookmaker has already paid out $1 million to bettors who put their money on Clinton winning.

However, Paddy Power has been burned in the past.

Betting odds in June favoured a "Remain" victory in the Brexit referendum.